Multicylinder engine



J. A. HOLMSTROM.

MULTICYLINDER ENGINE.

APPLICATION FILED OCT. 31. 1918.

Patented Nov. 16, 1920.

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J. A. HOLMSTROM.

MULTICYLINDER ENGINE.

APPLICATION FILED OCT. 31, 1918.

1,358,954 Y Patented NOV. 16, 1920.

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MULTICYLINDER ENGINE.

Specification of Letters Patent.

Patented Nov. 16, 1920.

Application filed October 31, 1918. Serial No. 260,561.

T 0 all whom it may concern:

Be it known that I, J OHAN AXEL HOLM- s'rRoM, a sub'ect of the King of Sweden, and resident of l illa Arovik, Viggbyholm, in the Kingdom of Sweden, have invented certain new and useful Improvements in Multicylinder Engines, of which the following is a specification, reference being had therein to the accompanyin drawings.

This invention re ates to a multi-cylinder engine (steam engine, pneumatic engine, internal combustion engine etc), in which the cylinders are located in groups with an arbitrary number of cylinders in each roup, the center lines of the cylinders of each group being disposed in substantially the same plane, forming an angle with the crank shaft, so that the engine is compact and requires a small space, which is of importance especially in multi-cylinder internal combustion engines for traders, flying machines etc. In order that the istons of the cylinders may be able to drive a common crank shaft, the engine is provided with one or more auxiliary crank shafts substantially parallel with the said common crank shaft, the cranks or pitmen of each group being connected by means of one or more rods or a cross head, which is caused b the cranks to move parallel with itself. wing to the fact that the cranks of the different groups form an angle with one another as in ordinary multi-cylinder engines, the said cross head is positively guided. The said shafts may, however, be connected by means of a gearing or the like. 'VVhen the engine is provided with two or more auxiliary crank shafts, the said shafts may be so located, that, also when there is only one group of cylinders, the said cross head is positively guided and the cranks aid one another in passing the dead points.

Figure 1 in the accompanying drawings shows in a vertical section and viewed from one end a multi-cylinder internal combustion engine arranged in accordance with this invention; in the said engine there are three cylinders in each group. Fig. 2 shows diagrammatically an internal combustion engine arranged in accordance with this invention and provided with four cylinders in each group. Fig. 3 shows diagrammatically an internal combustion engine with two cylinders in. each group. Fig. 4 illustrates the disposing of the crank shafts and the means connecting the same for the guiding of the cross head connecting the cranks in a positive manner even in engines provided with only one group of cylinders. Fig. 5 shows diagrammatically and in an end view an engine arranged in accordance with this invention and provided with means permitting one of the auxiliary crank shafts to reciprocate sidewise. Fig. 6 is a detail.

1, 2 and 3, Fig. 1, are three cylinders, which together make a group and drive a common shaft 4. In order that the motive power may be transmitted from all pistons 5 of the said cylinders to the shaft 4, the engine is provided with an auxiliar crank shaft'6, which is substantially paral el with the crank shaft 4. The cranks 7, 8 of the said shafts 4, 6, which cranks are parallel with one another and have the same length,

are connected by a rod or cross head 9, with which the pitmen 10 are connected. One or more groups of cylinders of the said type may be located behind the shown group. The cranks of the different groups form an angle with one another, in the manner known in ordinary engines, so that the engine is balanced and the cross head 9 of each group is positively guided.

Owing to the described arrangement the cross head alawys will move parallel with itself and the pistons 5 will act in the same manner as if connected directly with the crank 7. The cylinders 1, 2 and 3, evidently, are arranged accordin to the same system (two-stroke, three-stro eor siX-stroke-system) and may have a common valve gear, as shown. 11 designates the inlet valve for the fuel, and 12 is the outlet valve for the gases of combustion. The said valves 11, 12 communicate directly with the central cylinder 2 but may evidently, communicate with the cylinder 1 or 3. The valves are actuated by means of linkand lever-mechanisms 13, 14 by cam disks (not shown), provided on shafts 15, 16, which are rotated by the motor. The cam shafts may however be parallel with the cylinder groups respectively and form an angle with the shafts of the engine, as easily understood by those skilled in the art. Between the cylinders,

cocks 17, 18 are provided, which are so arranged, that the same, shifted into on position (see cook 17) connect the cylinders with one another, for admitting fuel from the central-cylinder to the lateral cylinders and for the exit of the gases of combustion from the cylinders last mentioned. If any one of the lateral cylinders should get out of work ing, it may be shut off from the central cylinder by shifting the cock (see cock 18) and connected directly with the outer air, While the remaining cylinder or cylinders continue in working. This arrangement is of great importance in engines provided on flying machines, adapted especially for use in war. The shaft 6 may, evidently, serve not only as an auxiliary shaft but also as a driving shaft, for instance of a propeller on a vessel or flying machine. The number of cylinders of each group as well as the number of shafts may be another than that shown in Fig. 1.

Thus, for instance, three crank shafts 19, 20, 21 are shown in Fig. 2, connected by a I rod or'cross'head 22, with which the pitmen 23, 24, 25 and 26 of four cylinders 27, 28, 29 and 30 are connected. The cylinders 31. 32, 33 and 34 communicate two by twt') and have a common supply conduit 35 for the fuel provided with valves 36, 37. The outlet valves for' the gases of combustion are designated by 38 and 39. Consequently, in the engine shown in Fig. 2, the central cylinders only are provided with inlet valves for the fuel, while the outlet valves for the gases of combustion are provided at the outer cylinders. The case ma however, be the reverse. Consequently, t ere is plenty of room for valves at each cylinder.

The shaft must not be located symmetrically in relation to the cylinders, as shown in Figs. 1 and 2, but may have any position within certain limits, for instance the posi-.

tion shown in Fig. 3. In the figure last mentioned there are two cylinders 40, 41 in each group and two shafts 42, 43. The said cylinders communicate with one another and are provided "with a common ignition device 44.; The shafts 42, 43 are so located, that the charge of fuel in the cylinder 41 is compressed and ignited somewhat earlier than the charge in the cylinder 40, which results in the ignition in the cylinder 40 being effected more gently, so to say.

The engine shown in Fig. 4 has three crank shafts 45, 46, 4?.and four cylinders 48, 49, 50, 51. The said shafts are located in the corners of a triangle and connected only by the cross head 52 located on the crank pins. Owing to the said position of the crank shafts the cranks aid one another in passing the dead points and the cross 55, 56 and 58, 59 are located on opposite sides of the shafts 53, 54. In Fig. 5 the cylinders and other parts of the engine except the shafts and the cranks are omitted. Owing to the fact that the cross heads 57, 60 during the rapid movement of the engine yield outward acted upon by the centrifugal force, the distance between the cranks 55, 56 and 58, 59 respectively will be reduced. This results in the crank pins and other parts being subjected to a great straining and wear. For removing this disadvantage one of the shafts for instance the shaft 54, is journaled in blocks 61, which are movable in stationary guides 62, so located, that they permit the blocks and the shaft 54 to move laterally, subjected to the action of the cross heads 57 and 60. Evidently, the said movement is very short and does not affect the action of the shaft 54, carrying for instance a propeller.

In Fig. 6 the shaft 54 is journaled in a bush 62, rotatably mounted in a ring 63, which can rotate in a stationary bearing 64. Two or more devices of the said construc tion are provided for the shaft 54. The bush 62 has an eccentric position in the ring 63. Owing to this arrangement the shaft 54 is able to move laterally to some extent sufficient for the stated purpose.

As seen from the drawings and the above description the pitmen of an arbitrary number of pistons may be connected with the cross head connecting the crank shafts. Consequently according to the invention multi-cylinder engines, may be made very compact. For instance, the cylinders of an engine having twelve cylinders may be located in three groups, each having four cylinders. The invention maybe adapted also to engines, provided with fixed shaft and rotating cylinders.

Having now described my invention, what I claim as new and desireto secure by Letters Patent is:

1. In a multi-cylinder engine the combination of a numberof cranks, a member connecting the pins ofthe said cranks, a plurality of working cylinders substantially perpendicular to.the said member and con necting rods transmitting motion from the pistons of the said cylinders to the, said member.

2. In a multi-cylinder engine the combination of a plurality of rows of substantially parallel cylinders, which rows are located one behind the other, a number of substantially parallel crank shafts, extending transversely of the said rows and each provided with parallel cranks corresponding to the rows of cylinders respectively, the cranks of the different rows forming an angle with one another, members connecting the cranks respectively of the said crank shafts, and

connecting rods transmitting motion from the pistons of the said cylinders to the said members.

8. In a multi-cylinder engine the combination with a number of substantially parallel cylinders of a number of uniformly rotating cranks located in the corners of a triangle, a beam connecting the pins of the said cranks and means connecting the pitmen of the cylinders with the said beam, the said beam moving parallel with itself.

4. In a multi-cylinder engine the combination with a number of substantially parallel cylinders of passages connecting the combustion chambers of the cylinders, cocks provided in the said passages and so arranged, that they can shut off the said passages and at the same time connect one of the cylinders with the outer air, a number of uniformly rotating cranks, a beam connecting the pins of the said cranks, and means connecting the pitmen of the cylinders with the said beam, the said beam moving parallel with itself.

5. In a multi-cylinder engine the combination with a number of substantially parallel cylinders of a number of uniformly rotating crank shafts a beam connecting the pins of the said crank shafts, and means connecting the pitmen of the cylinders with the said beam, the bearings of one of the crank shafts being stationary, While the bearing of the other shaft or shafts are so arranged that they permit the crank shafts to move laterally toward and from the stationary crank shaft.

In witness whereof, I have hereunto signed my name.

JOHAN AXEL 'HOLMSTROM. 

